title: Characteristics of exciton-polaritons in ZnO-based hybrid microcavities.
abstract: Wide bandgap semiconductors are promising materials for the development of polariton-based optoelectronic devices operating at room temperature (RT). We report the characteristics of ZnO-based microcavities (MCs) in the strong coupling regime at RT with a vacuum Rabi splitting of 72 meV. The impact of scattering states of excitons on polariton dispersion is investigated. Only the lower polariton branches (LPBs) can be clearly observed in ZnO MCs since the large vacuum Rabi splitting pushes the upper polariton branches (UPBs) into the scattering absorption states in the ZnO bulk active region. In addition, we systematically investigate the polariton relaxation bottleneck in bulk ZnO-based MCs. Angle-resolved photoluminescence measurements are performed from 100 to 300 K for different cavity-exciton detunings. A clear polariton relaxation bottleneck is observed at low temperature and large negative cavity detuning conditions. The bottleneck is suppressed with increasing temperature and decreasing detuning, due to more efficient phonon-assisted relaxation and a longer radiative lifetime of the polaritons.
authors.affiliation: Department of Photonics, National Chiao Tung University, Hsinchu, Taiwan.
authors.forename: Jun-Rong
authors.initials: JR
authors.lastname: Chen
authors.forename: Tien-Chang
authors.initials: TC
authors.lastname: Lu
authors.forename: Yung-Chi
authors.initials: YC
authors.lastname: Wu
authors.forename: Shiang-Chi
authors.initials: SC
authors.lastname: Lin
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Hsieh
authors.forename: Shing-Chung
authors.initials: SC
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Deng
mesh_terms: D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D008904:Miniaturization; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D015034:Zinc Oxide